split up vs break up

split up is a noun but break up is not a noun.

Word	Noun	Adjective	Verb	Adverb
split up	Yes	No	Yes	No
break up	No	No	Yes	No

As verbs, break up is a hyponym of split up; that is, break up is a word with a more specific, narrower meaning than split up:

As verbs, break up is a hypernym of split up; that is, break up is a word with a broader meaning than split up:

Other hypernyms of split up include break, part, separate, split, split up.

As verbs, split up and break up are synonyms defined as:

split up and break up: discontinue an association or relation; go different ways

Other synonyms of split up include break, part, separate, split.

split up (noun)	break up (noun)
an increase in the number of outstanding shares of a corporation without changing the shareholders' equity

split up (verb)	break up (verb)
become separated into pieces or fragments	laugh unrestrainedly
get a divorce; formally terminate a marriage	break or cause to break into pieces
discontinue an association or relation; go different ways	come to an end
separate into parts or portions	separate (substances) into constituent elements or parts
	cause to go into a solution
	cause to separate
	close at the end of a session
	bring the association of to an end or cause to break up
	make a break in
	set or keep apart
	break violently or noisily; smash
	attack with or as if with a pickaxe of ice or rocky ground, for example
	release ice
	destroy the completeness of a set of related items
	take apart into its constituent pieces
	suffer a nervous breakdown
	disband
	to cause to separate and go in different directions
	discontinue an association or relation; go different ways